Years ago on this very site, I imagined a 'headless' Mac that used a wirelessly-connected tablet as its screen. (I was 'The Steve Jobs Mind-Meld' back then, I think)
There have been apps that allow a certain amount on desktop activity via iPhone, but a move like the one I just described has not happened; the A7 forward may well change that, and since the only reason my Mac can't run 10.7 + is it's a 32-bit processor, we may se a complete shuffling of the Apple product lineup due to this. Many new things may become possible.
Imagine with me the real digital hub: headed or headless, powerful enough to serve files, media, print, etc AND powerful enough to provide each user with a convincing user experience, [i]even when everyone's using it[/i]; A7-heritage allows iPad 5 (6?) to provide touch-screen access to an account on the Mac, with all that implies. Monitor sales shrink, iMacs are repositioned, Mac Pro re-design gets utilized top to bottom. Thunderbolt becomes commodity. Mac sales soar. iPad sales soar. The end.
The pieces are coming together much more convincingly than I'd imagined.